A secret place in the desert

During the late 1950s, the Nevada desert near Groom Dry Lake echoed with the roar of jet engines as Lockheed's U-2 spyplane was put through its paces. The small airbase on the southern edge of the lakebed was called Watertown. There, Lockheed test pilots developed the airplane and its systems, while pilots assigned to the Central Intelligence Agency (CIA) trained for operational reconnaissance missions.

Just over the hills at Yucca Flat, the Atomic Energy Commission (AEC) was detonating nuclear bombs. Since Watertown was downwind of the Nevada Test Site (NTS), it received much of the radioactive fallout. Consequently, there was a standing agreement that Watertown personnel would be evacuated prior to a nuclear shot to limit their exposure. Most of the tests, and all of those involving full-scale nuclear explosions, took place more than 10 miles away.

One shot however took place on Watertown's doorstep.

One-Point Safe

The 1957 nuclear test series, called Operation Plumbbob, included 24 nuclear detonations and six safety experiments. The first shot of the series was a safety experiment called Project 57. A test of this type is usually conducted to determine that a weapon or warhead damaged in an accident will not detonate with a nuclear yield, even if some or all of the high explosive components burn or detonate. While not producing a nuclear explosion, such a detonation usually spreads a substantial amount of plutonium into the atmosphere and across the surrounding landscape. As such, safety experiments are also known as plutonium dispersal tests.

Such experiments were necessary because aircraft crashes and other operational and logistical accidents involving nuclear weapons could result in one-point detonation of the weapon's high explosive components, producing no nuclear yield but contaminating the local area with radioactive materials. Project 57 was designed to study the particle physics of plutonium, biomedicine of animals exposed to the fallout, radiation monitoring, and decontamination of plutonium-contaminated surfaces.

According to Chuck Hansen, in U.S. Nuclear Weapons: The Secret History, the weapon used was an XW-25 warhead, with a design yield of 1.5 kilotons. The XW-25 was 26.7-inches long, 17.4-inches wide, and weighed about 218 pounds. It was designed to be the warhead for the Douglas MB-1 Genie air-to-air-missile.

A formerly secret document detailing the minutes of the first meeting on Project 57 states that the weapon was to be "fired on the ground at the bottom detonator."